1. Field of the Invention
This invention relates generally to electrical connectors, and more particularly to a bistable zero insertion force connector assembly wherein the mating ends of conductive contact elements in the first stable or unengaged state are placeable in mating proximity to terminal connecting elements with zero force and zero contact therebetween, while in the second stable or engaged state the mating ends and corresponding terminal connecting elements are maintained in secured engagement.
2. Prior Art
The advent of the parallel processing concept wherein several processors or microprocessors are electrically interconnected to several memory, control, input/output, and auxiliary units has necessitated that vast arrays of PC boards, circuit cards, banks of terminal connectors and the like be electrically integrated. To facilitate such integration it is advantageous to mass engage one or more such arrays to connector assemblies in a single operation with a minimal force.
And, with the increasing tendency towards miniaturization and high-density packing of PC boards, circuit cards, and terminal connector banks, the number of contact points per array is substantially increased, thereby multiplying the force necessary to mass engage such arrays to connector assemblies to the point where it is very difficult from a physical force standpoint to make such connections. Further complicating the electrical integration of such arrays is the fragility of the contact points of the arrays and the electronic devices or components to be integrated thereto, such that alignment of such arrays with connector assemblies for mass engagement must be accomplished with minimal force therebetween to allow insertion and to preclude damage to the contact points and/or the electronic elements of the assemblies. Any such damage will result in incomplete electrical connection or circuit failure.
Zero insertion force (ZIF) connector assemblies are well known in the prior art. Representative examples of such ZIF connector assemblies include U.S. Pat. Nos. 4,576,427, Re. 31,929, 4,332,431, and 4,266,840. Generally, such ZIF connector assemblies comprise complex contact elements, assembly housings, and/or actuation or mass engagement means that allow male and female connector pairs to be inserted and subsequently engaged. The complexity of such ZIF connector assemblies increases the costs thereof, in manufacturing the elements thereof, in preloading or inserting the connector elements within the assembly housing, and in the time consumed in preloading, and lowers the overall reliability. Moreover, the complexity of such ZIF connector assemblies makes them less readily adaptable for miniaturization or high density packing. These factors militate against the use of such ZIF connector assemblies where numerous arrays must be electrically integrated.
A further problem is inherent in the use of prior art ZIF connector assemblies where numerous arrays must be electrically integrated. Although ZIF connector assemblies permit large arrays to be disposed in mating proximity thereto with zero force, the physical force necessary to accomplish engagement therebetween becomes prohibitively large as the number of contact points increases. Thus, miniaturization is limited by the resulting increase in connection force, be it throught insertion or engagement.